A lot of you may be familiar with the anime Kimi ga Nozomu Eien (Rumbling Hearts in America). KimiNozo was actually based on a visual novel.
In the game, you can choose what happens in the story. Didn't like how the anime turned out? Play the game and choose what happens. You can make Takayuki stay faithful with Haruka, stick to Mitsuki, or even date the annoying waitress Ayu. Almost every girl in the anime (and one extra girl that is game-only) has a "route" with multiple endings. Whereas the game only followed one route, the game has dozens of ways that it could turn out. (It should also be noted that the anime takes one of the worst routes of the game - the game is much, much deeper and has more fleshed out characters) Along with the eight different girls with routes, there are dozens of endings (including a harem ending with Haruka, Mitsuki, and Akane =P), "afterstories" for some of the characters (the ~NextSeason~ anime was an adaption of Haruka's after story), a special side game where the accident didn't happen, and many other options.

A group known as Amaterasu Translations that translates visual novels (basically novles for the PC where you can choose what happens, ala a CYOA book) is considering to translate the Kimi ga Nozomu Eien game if it wins in their new translation poll. The poll will start on November 23rd at 6:00 PM US Pacific Time and last for 24 hours.